1. The Field of the Invention
The present invention is in the field of medical devices, for example scalpels and other surgical cutting devices.
2. The Relevant Technology
Medical practitioners often close a wound or opening within a patient (e.g., during surgery) with sutures. Scalpels are often used as needed in performing the surgery, and then are often used for cutting the ends of sutures employed to close up the wound or opening within the patient's tissue. Depending on the nature of the procedure, sutures can be placed adjacent to a main artery or vein, and as such, any misplacement of the scalpel when cutting the suture (e.g., caused by an accidental sneeze, cough, or otherwise) could potentially be disastrous. As an alternative, it is possible to cut the sutures with scissors, but this requires an additional step and can be something of a nuisance to the practitioner, as the practitioner already has a scalpel handy.
Many scalpels include a safety sheath that covers the blade end of the scalpel. In order to use the blade (e.g., for cutting tissue or a suture) the sheath must be retracted or removed, or a retractable blade must be extended beyond the sheath, so as to expose the blade for use.
Some efforts have been made to provide an ability to access the scalpel blade for cutting a suture while the blade is safely sheathed so as to prevent accidental cuts to the patient and/or practitioner. One such configuration is shown in U.S. Patent Application 2009/0157110, which includes a notch opening 17 in the side of the sheath 18 to allow a suture to be cut without exposing blade 20. As the suture is inserted into notch opening 17, tension between the suture and the blade 20 is used to cut the suture.
Another configuration is shown in FIG. 1B, which is taken from U.S. Patent Application 2005/0234481, and which discloses a dedicated suture cutting device in which the blade 115 is somewhat protected within an alcove at the distal end of the device. Similar to the device shown in FIG. 1A, the suture is pulled tight against the blade and tension between the blade and suture cuts the suture. Such a device is not capable of performing the traditional functions of a scalpel.
Although suture-cutting devices have been proposed, there still exists a need for improved configurations that effectively sheath the blade from accidental exposure, while providing easy, fast, and efficient cutting of a suture.